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Message-ID: <20120912133925.GP5732@arwen.pp.htv.fi>
Date: Wed, 12 Sep 2012 16:39:27 +0300
From: Felipe Balbi <balbi@...com>
To: Shubhrajyoti D <shubhrajyoti@...com>
Cc: spi-devel-general@...ts.sourceforge.net,
broonie@...nsource.wolfsonmicro.com, grant.likely@...retlab.ca,
linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] spi: omap2-mcspi: Cleanup the omap2_mcspi_txrx_dma
function
On Tue, Sep 11, 2012 at 12:13:20PM +0530, Shubhrajyoti D wrote:
> Currently in omap2_mcspi_txrx_dma the tx and the rx support is
> interleaved. Make the rx related code in omap2_mcspi_rx_dma
> and the tx related code omap2_mcspi_tx_dma and call the functions.
>
> While at it remove the braces in the if statements which has only
> one line.
> Also fix ["foo * bar" to "foo *bar"] warn for the rx and tx variables.
>
> Only a cleanup no functional change.
>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@...com>
I just tested this on my pandaboard by shorting out MISO and MOSI (since
panda doesn't have any clients on spi bus) and using spidev:
# ./spidev_test -D /dev/spidev
spi mode: 0
bits per word: 8
max speed: 500000 Hz (500 KHz)
FF FF FF FF FF FF
40 00 00 00 00 95
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
DE AD BE EF BA AD
F0 0D
./spidev_test -D /dev/spidev -s 24000000
spi mode: 0
bits per word: 8
max speed: 24000000 Hz (24000 KHz)
FF FF FF FF FF FF
40 00 00 00 00 95
FF FF FF FF FF FF
FF FF FF FF FF FF
FF FF FF FF FF FF
DE AD BE EF BA AD
F0 0D
seems to be working fine (at least from my quick tests)
Tested-by: Felipe Balbi <balbi@...com>
> ---
> drivers/spi/spi-omap2-mcspi.c | 256 +++++++++++++++++++++++------------------
> 1 files changed, 144 insertions(+), 112 deletions(-)
>
> diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
> index 1c1dd34..dd8fc88 100644
> --- a/drivers/spi/spi-omap2-mcspi.c
> +++ b/drivers/spi/spi-omap2-mcspi.c
> @@ -315,49 +315,27 @@ static void omap2_mcspi_tx_callback(void *data)
> omap2_mcspi_set_dma_req(spi, 0, 0);
> }
>
> -static unsigned
> -omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
> +static void omap2_mcspi_tx_dma(struct spi_device *spi,
> + struct spi_transfer *xfer,
> + struct dma_slave_config cfg)
> {
> struct omap2_mcspi *mcspi;
> - struct omap2_mcspi_cs *cs = spi->controller_state;
> struct omap2_mcspi_dma *mcspi_dma;
> unsigned int count;
> - int word_len, element_count;
> - int elements = 0;
> - u32 l;
> u8 * rx;
> const u8 * tx;
> void __iomem *chstat_reg;
> - struct dma_slave_config cfg;
> - enum dma_slave_buswidth width;
> - unsigned es;
> + struct omap2_mcspi_cs *cs = spi->controller_state;
>
> mcspi = spi_master_get_devdata(spi->master);
> mcspi_dma = &mcspi->dma_channels[spi->chip_select];
> - l = mcspi_cached_chconf0(spi);
> + count = xfer->len;
>
> + rx = xfer->rx_buf;
> + tx = xfer->tx_buf;
> chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
>
> - if (cs->word_len <= 8) {
> - width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> - es = 1;
> - } else if (cs->word_len <= 16) {
> - width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> - es = 2;
> - } else {
> - width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> - es = 4;
> - }
> -
> - memset(&cfg, 0, sizeof(cfg));
> - cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
> - cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
> - cfg.src_addr_width = width;
> - cfg.dst_addr_width = width;
> - cfg.src_maxburst = 1;
> - cfg.dst_maxburst = 1;
> -
> - if (xfer->tx_buf && mcspi_dma->dma_tx) {
> + if (mcspi_dma->dma_tx) {
> struct dma_async_tx_descriptor *tx;
> struct scatterlist sg;
>
> @@ -368,7 +346,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
> sg_dma_len(&sg) = xfer->len;
>
> tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
> - DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> + DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> if (tx) {
> tx->callback = omap2_mcspi_tx_callback;
> tx->callback_param = spi;
> @@ -377,8 +355,50 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
> /* FIXME: fall back to PIO? */
> }
> }
> + dma_async_issue_pending(mcspi_dma->dma_tx);
> + omap2_mcspi_set_dma_req(spi, 0, 1);
>
> - if (xfer->rx_buf && mcspi_dma->dma_rx) {
> + wait_for_completion(&mcspi_dma->dma_tx_completion);
> + dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
> + DMA_TO_DEVICE);
> +
> + /* for TX_ONLY mode, be sure all words have shifted out */
> + if (rx == NULL) {
> + if (mcspi_wait_for_reg_bit(chstat_reg,
> + OMAP2_MCSPI_CHSTAT_TXS) < 0)
> + dev_err(&spi->dev, "TXS timed out\n");
> + else if (mcspi_wait_for_reg_bit(chstat_reg,
> + OMAP2_MCSPI_CHSTAT_EOT) < 0)
> + dev_err(&spi->dev, "EOT timed out\n");
> + }
> +}
> +
> +static unsigned
> +omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
> + struct dma_slave_config cfg,
> + unsigned es)
> +{
> + struct omap2_mcspi *mcspi;
> + struct omap2_mcspi_dma *mcspi_dma;
> + unsigned int count;
> + u32 l;
> + int elements = 0;
> + int word_len, element_count;
> + struct omap2_mcspi_cs *cs = spi->controller_state;
> + mcspi = spi_master_get_devdata(spi->master);
> + mcspi_dma = &mcspi->dma_channels[spi->chip_select];
> + count = xfer->len;
> + word_len = cs->word_len;
> + l = mcspi_cached_chconf0(spi);
> +
> + if (word_len <= 8)
> + element_count = count;
> + else if (word_len <= 16)
> + element_count = count >> 1;
> + else /* word_len <= 32 */
> + element_count = count >> 2;
> +
> + if (mcspi_dma->dma_rx) {
> struct dma_async_tx_descriptor *tx;
> struct scatterlist sg;
> size_t len = xfer->len - es;
> @@ -393,108 +413,120 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
> sg_dma_len(&sg) = len;
>
> tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
> - DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> + DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
> + DMA_CTRL_ACK);
> if (tx) {
> tx->callback = omap2_mcspi_rx_callback;
> tx->callback_param = spi;
> dmaengine_submit(tx);
> } else {
> - /* FIXME: fall back to PIO? */
> - }
> - }
> -
> - count = xfer->len;
> - word_len = cs->word_len;
> -
> - rx = xfer->rx_buf;
> - tx = xfer->tx_buf;
> -
> - if (word_len <= 8) {
> - element_count = count;
> - } else if (word_len <= 16) {
> - element_count = count >> 1;
> - } else /* word_len <= 32 */ {
> - element_count = count >> 2;
> - }
> -
> - if (tx != NULL) {
> - dma_async_issue_pending(mcspi_dma->dma_tx);
> - omap2_mcspi_set_dma_req(spi, 0, 1);
> - }
> -
> - if (rx != NULL) {
> - dma_async_issue_pending(mcspi_dma->dma_rx);
> - omap2_mcspi_set_dma_req(spi, 1, 1);
> - }
> -
> - if (tx != NULL) {
> - wait_for_completion(&mcspi_dma->dma_tx_completion);
> - dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
> - DMA_TO_DEVICE);
> -
> - /* for TX_ONLY mode, be sure all words have shifted out */
> - if (rx == NULL) {
> - if (mcspi_wait_for_reg_bit(chstat_reg,
> - OMAP2_MCSPI_CHSTAT_TXS) < 0)
> - dev_err(&spi->dev, "TXS timed out\n");
> - else if (mcspi_wait_for_reg_bit(chstat_reg,
> - OMAP2_MCSPI_CHSTAT_EOT) < 0)
> - dev_err(&spi->dev, "EOT timed out\n");
> + /* FIXME: fall back to PIO? */
> }
> }
>
> - if (rx != NULL) {
> - wait_for_completion(&mcspi_dma->dma_rx_completion);
> - dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
> - DMA_FROM_DEVICE);
> - omap2_mcspi_set_enable(spi, 0);
> + dma_async_issue_pending(mcspi_dma->dma_rx);
> + omap2_mcspi_set_dma_req(spi, 1, 1);
>
> - elements = element_count - 1;
> + wait_for_completion(&mcspi_dma->dma_rx_completion);
> + dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
> + DMA_FROM_DEVICE);
> + omap2_mcspi_set_enable(spi, 0);
>
> - if (l & OMAP2_MCSPI_CHCONF_TURBO) {
> - elements--;
> + elements = element_count - 1;
>
> - if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
> - & OMAP2_MCSPI_CHSTAT_RXS)) {
> - u32 w;
> -
> - w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
> - if (word_len <= 8)
> - ((u8 *)xfer->rx_buf)[elements++] = w;
> - else if (word_len <= 16)
> - ((u16 *)xfer->rx_buf)[elements++] = w;
> - else /* word_len <= 32 */
> - ((u32 *)xfer->rx_buf)[elements++] = w;
> - } else {
> - dev_err(&spi->dev,
> - "DMA RX penultimate word empty");
> - count -= (word_len <= 8) ? 2 :
> - (word_len <= 16) ? 4 :
> - /* word_len <= 32 */ 8;
> - omap2_mcspi_set_enable(spi, 1);
> - return count;
> - }
> - }
> + if (l & OMAP2_MCSPI_CHCONF_TURBO) {
> + elements--;
>
> if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
> - & OMAP2_MCSPI_CHSTAT_RXS)) {
> + & OMAP2_MCSPI_CHSTAT_RXS)) {
> u32 w;
>
> w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
> if (word_len <= 8)
> - ((u8 *)xfer->rx_buf)[elements] = w;
> + ((u8 *)xfer->rx_buf)[elements++] = w;
> else if (word_len <= 16)
> - ((u16 *)xfer->rx_buf)[elements] = w;
> + ((u16 *)xfer->rx_buf)[elements++] = w;
> else /* word_len <= 32 */
> - ((u32 *)xfer->rx_buf)[elements] = w;
> + ((u32 *)xfer->rx_buf)[elements++] = w;
> } else {
> - dev_err(&spi->dev, "DMA RX last word empty");
> - count -= (word_len <= 8) ? 1 :
> - (word_len <= 16) ? 2 :
> - /* word_len <= 32 */ 4;
> + dev_err(&spi->dev, "DMA RX penultimate word empty");
> + count -= (word_len <= 8) ? 2 :
> + (word_len <= 16) ? 4 :
> + /* word_len <= 32 */ 8;
> + omap2_mcspi_set_enable(spi, 1);
> + return count;
> }
> - omap2_mcspi_set_enable(spi, 1);
> }
> + if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
> + & OMAP2_MCSPI_CHSTAT_RXS)) {
> + u32 w;
> +
> + w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
> + if (word_len <= 8)
> + ((u8 *)xfer->rx_buf)[elements] = w;
> + else if (word_len <= 16)
> + ((u16 *)xfer->rx_buf)[elements] = w;
> + else /* word_len <= 32 */
> + ((u32 *)xfer->rx_buf)[elements] = w;
> + } else {
> + dev_err(&spi->dev, "DMA RX last word empty");
> + count -= (word_len <= 8) ? 1 :
> + (word_len <= 16) ? 2 :
> + /* word_len <= 32 */ 4;
> + }
> + omap2_mcspi_set_enable(spi, 1);
> + return count;
> +}
> +
> +static unsigned
> +omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
> +{
> + struct omap2_mcspi *mcspi;
> + struct omap2_mcspi_cs *cs = spi->controller_state;
> + struct omap2_mcspi_dma *mcspi_dma;
> + unsigned int count;
> + u32 l;
> + u8 *rx;
> + const u8 *tx;
> + struct dma_slave_config cfg;
> + enum dma_slave_buswidth width;
> + unsigned es;
> +
> + mcspi = spi_master_get_devdata(spi->master);
> + mcspi_dma = &mcspi->dma_channels[spi->chip_select];
> + l = mcspi_cached_chconf0(spi);
> +
> +
> + if (cs->word_len <= 8) {
> + width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> + es = 1;
> + } else if (cs->word_len <= 16) {
> + width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> + es = 2;
> + } else {
> + width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + es = 4;
> + }
> +
> + memset(&cfg, 0, sizeof(cfg));
> + cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
> + cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
> + cfg.src_addr_width = width;
> + cfg.dst_addr_width = width;
> + cfg.src_maxburst = 1;
> + cfg.dst_maxburst = 1;
> +
> + rx = xfer->rx_buf;
> + tx = xfer->tx_buf;
> +
> + count = xfer->len;
> +
> + if (tx != NULL)
> + omap2_mcspi_tx_dma(spi, xfer, cfg);
> +
> + if (rx != NULL)
> + return omap2_mcspi_rx_dma(spi, xfer, cfg, es);
> +
> return count;
> }
>
> --
> 1.7.5.4
>
> --
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--
balbi
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